Datasheet

RL78/L12 CHAPTER 14 LCD CONTROLLER/DRIVER
R01UH0330EJ0200 Rev.2.00 647
Dec 13, 2013
14.10.2 Two-time-slice display example
Figure 14-31 shows how the 6-digit LCD panel having the display pattern shown in Figure 14-30 is connected to the
segment signals (SEG0 to SEG23) and the common signals (COM0 and COM1). This example displays data “12345.6” in
the LCD panel. The contents of the display data register (F0400H to F0417H) correspond to this display.
The following description focuses on numeral “3” ( ) displayed in the fourth digit. To display “3” in the LCD panel, it is
necessary to apply the select or deselect voltage to the SEG12 to SEG15 pins according to Table 14-16 at the timing of
the common signals COM0 and COM1; see Figure 14-30 for the relationship between the segment signals and LCD
segments.
Table 14-16. Select and Deselect Voltages (COM0 and COM1)
Segment
Common
SEG12 SEG13 SEG14 SEG15
COM0 Select Select Deselect Deselect
COM1 Deselect Select Select Select
According to Table 14-16, it is determined that the display data register location (F040FH) that corresponds to SEG15
must contain xx10.
Figure 14-32 shows examples of LCD drive waveforms between the SEG15 signal and each common signal. When the
select voltage is applied to SEG15 at the timing of COM1, an alternate rectangle waveform, +V
LCD/−VLCD, is generated to
turn on the corresponding LCD segment.
Figure 14-30. Two-Time-Slice LCD Display Pattern and Electrode Connections
SEG 4n+2
SEG 4n+3
SEG 4n+1
SEG 4n
COM0
COM1
Remark 30-pin products: n = 0 to 2
44-pin products: n = 0 to 4
48-pin products: n = 0 to 5
52-pin products: n = 0 to 6
64-pin products: n = 0 to 8